remarkable-linux/include/linux/igmp.h
David L Stevens ca9b907d14 [IPV4]: multicast API "join" issues
This patch corrects a few problems with the IP_ADD_MEMBERSHIP
socket option:

1) The existing code makes an attempt at reference counting joins when
   using the ip_mreqn/imr_ifindex interface. Joining the same group
   on the same socket is an error, whatever the API. This leads to
   unexpected results when mixing ip_mreqn by index with ip_mreqn by
   address, ip_mreq, or other API's. For example, ip_mreq followed by
   ip_mreqn of the same group will "work" while the same two reversed
   will not.
           Fixed to always return EADDRINUSE on a duplicate join and
   removed the (now unused) reference count in ip_mc_socklist.

2) The group-search list in ip_mc_join_group() is comparing a full 
   ip_mreqn structure and all of it must match for it to find the
   group. This doesn't correctly match a group that was joined with
   ip_mreq or ip_mreqn with an address (with or without an index). It
   also doesn't match groups that are joined by different addresses on
   the same interface. All of these are the same multicast group,
   which is identified by group address and interface index.
           Fixed the check to correctly match groups so we don't get
   duplicate group entries on the ip_mc_socklist.

3) The old code allocates a multicast address before searching for
   duplicates requiring it to free in various error cases. This
   patch moves the allocate until after the search and
   igmp_max_memberships check, so never a need to allocate, then free
   an entry.

Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-08 17:38:07 -07:00

219 lines
5.7 KiB
C

/*
* Linux NET3: Internet Group Management Protocol [IGMP]
*
* Authors:
* Alan Cox <Alan.Cox@linux.org>
*
* Extended to talk the BSD extended IGMP protocol of mrouted 3.6
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _LINUX_IGMP_H
#define _LINUX_IGMP_H
#include <asm/byteorder.h>
/*
* IGMP protocol structures
*/
/*
* Header in on cable format
*/
struct igmphdr
{
__u8 type;
__u8 code; /* For newer IGMP */
__u16 csum;
__u32 group;
};
/* V3 group record types [grec_type] */
#define IGMPV3_MODE_IS_INCLUDE 1
#define IGMPV3_MODE_IS_EXCLUDE 2
#define IGMPV3_CHANGE_TO_INCLUDE 3
#define IGMPV3_CHANGE_TO_EXCLUDE 4
#define IGMPV3_ALLOW_NEW_SOURCES 5
#define IGMPV3_BLOCK_OLD_SOURCES 6
struct igmpv3_grec {
__u8 grec_type;
__u8 grec_auxwords;
__u16 grec_nsrcs;
__u32 grec_mca;
__u32 grec_src[0];
};
struct igmpv3_report {
__u8 type;
__u8 resv1;
__u16 csum;
__u16 resv2;
__u16 ngrec;
struct igmpv3_grec grec[0];
};
struct igmpv3_query {
__u8 type;
__u8 code;
__u16 csum;
__u32 group;
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u8 qrv:3,
suppress:1,
resv:4;
#elif defined(__BIG_ENDIAN_BITFIELD)
__u8 resv:4,
suppress:1,
qrv:3;
#else
#error "Please fix <asm/byteorder.h>"
#endif
__u8 qqic;
__u16 nsrcs;
__u32 srcs[0];
};
#define IGMP_HOST_MEMBERSHIP_QUERY 0x11 /* From RFC1112 */
#define IGMP_HOST_MEMBERSHIP_REPORT 0x12 /* Ditto */
#define IGMP_DVMRP 0x13 /* DVMRP routing */
#define IGMP_PIM 0x14 /* PIM routing */
#define IGMP_TRACE 0x15
#define IGMPV2_HOST_MEMBERSHIP_REPORT 0x16 /* V2 version of 0x11 */
#define IGMP_HOST_LEAVE_MESSAGE 0x17
#define IGMPV3_HOST_MEMBERSHIP_REPORT 0x22 /* V3 version of 0x11 */
#define IGMP_MTRACE_RESP 0x1e
#define IGMP_MTRACE 0x1f
/*
* Use the BSD names for these for compatibility
*/
#define IGMP_DELAYING_MEMBER 0x01
#define IGMP_IDLE_MEMBER 0x02
#define IGMP_LAZY_MEMBER 0x03
#define IGMP_SLEEPING_MEMBER 0x04
#define IGMP_AWAKENING_MEMBER 0x05
#define IGMP_MINLEN 8
#define IGMP_MAX_HOST_REPORT_DELAY 10 /* max delay for response to */
/* query (in seconds) */
#define IGMP_TIMER_SCALE 10 /* denotes that the igmphdr->timer field */
/* specifies time in 10th of seconds */
#define IGMP_AGE_THRESHOLD 400 /* If this host don't hear any IGMP V1 */
/* message in this period of time, */
/* revert to IGMP v2 router. */
#define IGMP_ALL_HOSTS htonl(0xE0000001L)
#define IGMP_ALL_ROUTER htonl(0xE0000002L)
#define IGMPV3_ALL_MCR htonl(0xE0000016L)
#define IGMP_LOCAL_GROUP htonl(0xE0000000L)
#define IGMP_LOCAL_GROUP_MASK htonl(0xFFFFFF00L)
/*
* struct for keeping the multicast list in
*/
#ifdef __KERNEL__
#include <linux/skbuff.h>
#include <linux/in.h>
struct ip_sf_socklist
{
unsigned int sl_max;
unsigned int sl_count;
__u32 sl_addr[0];
};
#define IP_SFLSIZE(count) (sizeof(struct ip_sf_socklist) + \
(count) * sizeof(__u32))
#define IP_SFBLOCK 10 /* allocate this many at once */
/* ip_mc_socklist is real list now. Speed is not argument;
this list never used in fast path code
*/
struct ip_mc_socklist
{
struct ip_mc_socklist *next;
struct ip_mreqn multi;
unsigned int sfmode; /* MCAST_{INCLUDE,EXCLUDE} */
struct ip_sf_socklist *sflist;
};
struct ip_sf_list
{
struct ip_sf_list *sf_next;
__u32 sf_inaddr;
unsigned long sf_count[2]; /* include/exclude counts */
unsigned char sf_gsresp; /* include in g & s response? */
unsigned char sf_oldin; /* change state */
unsigned char sf_crcount; /* retrans. left to send */
};
struct ip_mc_list
{
struct in_device *interface;
unsigned long multiaddr;
struct ip_sf_list *sources;
struct ip_sf_list *tomb;
unsigned int sfmode;
unsigned long sfcount[2];
struct ip_mc_list *next;
struct timer_list timer;
int users;
atomic_t refcnt;
spinlock_t lock;
char tm_running;
char reporter;
char unsolicit_count;
char loaded;
unsigned char gsquery; /* check source marks? */
unsigned char crcount;
};
/* V3 exponential field decoding */
#define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
#define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
((value) < (thresh) ? (value) : \
((IGMPV3_MASK(value, nbmant) | (1<<(nbmant+nbexp))) << \
(IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
#define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
#define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
extern int ip_check_mc(struct in_device *dev, u32 mc_addr, u32 src_addr, u16 proto);
extern int igmp_rcv(struct sk_buff *);
extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
extern void ip_mc_drop_socket(struct sock *sk);
extern int ip_mc_source(int add, int omode, struct sock *sk,
struct ip_mreq_source *mreqs, int ifindex);
extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
struct ip_msfilter __user *optval, int __user *optlen);
extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
struct group_filter __user *optval, int __user *optlen);
extern int ip_mc_sf_allow(struct sock *sk, u32 local, u32 rmt, int dif);
extern void ip_mr_init(void);
extern void ip_mc_init_dev(struct in_device *);
extern void ip_mc_destroy_dev(struct in_device *);
extern void ip_mc_up(struct in_device *);
extern void ip_mc_down(struct in_device *);
extern void ip_mc_dec_group(struct in_device *in_dev, u32 addr);
extern void ip_mc_inc_group(struct in_device *in_dev, u32 addr);
#endif
#endif